[单项选择]Small children often wonder what keeps the earth （　） in space.
A. in order
B. in place
C. in nature
D. in practice

[单项选择]The children （　） very quiet; I wonder what they（　）up to.
A. were; are being
B. are being; are
C. are; do
D. are being; do

[单项选择]People who own dogs often remark on what good company they are and what fun they have together.（）
A. 拥有狗的那些人经常评论说狗是多么好的朋友，和它们一起有很多乐趣。
B. 养狗的那些人经常说他们的狗是多么好的伙伴，同它们玩多么有趣。
C. 有狗的人常谈论他们的狗是他们的好伙伴，和狗在一起他们很开心。
D. 养狗的人常说狗是他们的好朋友，同它们玩很有趣。

[简答题]Too often we believe what accounts for other’s success is some special secret or a lucky break, __________ (但成功却很少如何神秘).

[填空题]The average surface temperature of Earth keeps around 15℃.

[简答题]Television，it is often said，keeps one informed about current events，and allows one to follow the latest developments in science and politics．The most distant countries and the strangest customs are brought right into one sitting room．It could be argued．that the radio performs this service just as well；but on television everything is much more living，much more real．Yet here again there is a danger．

[简答题]Television, it is often said, keeps one informed about current events, allows one to follow the latest developments in science and politics, and offers an endless number of programs which are both instructive and entertaining. It seems that television has become indispensable (必不可少 )and irreplaceable in our life. One can only imagine what our life will be like without it.

[单项选择]
A laser pointer is a small (often battery-operated) laser device designed for pointing at objects by illuminating them with a collimated visible laser beam. Most laser pointers, particularly the cheap ones, contain a small GalnP/AIGaInP laser diode operating somewhere in the red spectral region. Some significantly more expensive pointers emit green or even blue light and normally contain a small diode-pumped solid state laser with a nonlinear crystal for frequency doubling.
A typical use of a hand-held laser pointer is to point at some screen or chart during a presentation, e.g. a conference talk. This is convenient because it can be done from a large distance and requires only a rather small device. However, the visibility of the generated spot on the screen is often poor (particularly for red laser pointers with relatively long emission wavelength), and a fast moving light spot can h
A. By giving warnings under different occasions.
B. By listing some standards that the manufactures should follow.
C. By comparing different types of lasers.
D. By demonstrating the side-effects of lasers.